The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 10, 1995
Filed:
Aug. 12, 1993
Adrianus G Bouwer, Eindhoven, NL;
Frank B Sperling, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
A transmission mechanism for converting a rotary movement into a translatory movement includes an internal and an external coupling member which have cooperating double thread systems made of a magnetizable material. The external coupling member includes a series of permanent magnets which are polarized in an axial direction and are provided at regular intervals between the individual threads of the thread system so that the individual threads each form a common pole shoe for the permanent magnets providing a maximum magnetic flux density along the portion of the thread system containing the permanent magnets. The presence of a non-magnetizable material between the threads provides that the mutually facing walls of the coupling members are smooth, and a static gas bearing can be applied between these walls. A suitable application of the transmission mechanism is in a positioning device which in turn is eminently suitable for use in an optical lithographic device for the manufacture of semiconductor substrates.